This invention relates generally to single strand continuous rolling mills for billets, bars and the like, having straddle-mounted work rolls arranged in pairs along the rolling line, with the axes of successive work roll pairs being angularly offset to eliminate product twisting.
Rolling mills of this general type have been known for many years, as evidenced for example by U.S. Pat. Nos. 113,708 (Tranter et al) and 1,858,990 (Foren), and by German Pat. No. 742,990 (Wegner). In these prior art mills, the work roll pairs are each contained in separate housings which are mounted in spaced relationship along the rolling line, thus occupying a considerable amount of mill floor space. Moreover, when a roll change is required, the separate housings either must be dismantled while on the rolling line, or replaced entirely by spare housings containing other work rolls. The former alternative results in prolonged and costly mill down time, whereas the latter alternative requires a considerable capital investment in spare parts.
There are also multi-strand rolling mills of the type shown in U.S. Pat. No. 3,675,456 (Sieurin) which incorporate transfer devices for laterally shifting roll packages into and out of a succession of horizontal roll housings. Here again, however, the roll housings are separate structures spaced at considerable distances from each other along the rolling line.
The present invention represents a somewhat radical departure from conventional practice, with one of its principal objectives being the provision of an extremely compact single strand continuous rolling mill having a plurality of roll packages, each including pairs of work rolls straddle-mounted between bearing chocks, with the roll axes of successive roll packages being arranged at 90.degree. relative to each other. Compactness is made possible to a large extent by containing the roll packages in closely spaced relationship within a unitary housing structure.
Another object of the present invention is the provision of a compact rolling mill of the above-described type having means for transferring the roll packages in a common lateral direction between operative rolling positions contained within the unitary housing structure, and extracted inoperative positions on one side thereof.
A further object of the present invention is the provision of means for accommodating the aforesaid lateral extraction of roll packages either singly or as a group, and with or without a stalled product length threaded therethrough.